Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2019
Abstract
Edible seaweed biomass is a valuable alternative feed ingredient for livestock. The composition of seaweeds is highly variable, with large differences in proteins, minerals, lipids and carbohydrates. Species, season, harvesting year, habitat, and prevailing proximate environmental conditions account for this variation. Using seaweeds as a protein source for production animals is of interest. Studies suggest that some seaweed species may have bioactive compounds with antimethanogenic properties. To investigate the effect of the red seaweed Porphyra ssp on enteric methane produced by sheep an in vivo study was carried out with 24 Norwegian White ewes. The ewes were allocated into four groups receiving a control diet or one of three supplemented diets. All groups were fed grass silage ad libitum, crushed oat and mineral pellets; the three supplemented diets included a protein source where dried and powdered Porphyra ssp. was compared with white clover silage or pelleted soybean meal. The ewes were fed their respective diets for a two-week adaptation period and a 72-h experimental period during which methane was measured individually using open-circuit respiration chambers. Weight changes and methane production (L CH4/kg DM intake) were analysed using the GLM procedure with diet as fixed effect. No differences in weight changes and methane production between diets were found. Diet did not affect weight changes and methane production but DM intake was higher (P<0.001) for diets including soybean and macroalgae than white clover. Feeding red macroalgae showed no reduction in enteric methane production compared to the control diet.
Abstract
We determined how conidia of arthropod-pathogenic fungi on leaves affected the behavior of two predators—Orius majusculus (Hemiptera: Anthocoridae) and Phytoseiulus persimilis (Acari: Phytoseiidae)—when offered a choice between preying on two-spotted spider mites, Tetranychus urticae (Acari: Tetranychidae), in the presence or absence of infective conidia of Metarhizium brunneum (Ascomycota: Hypocreales) and Neozygites floridana (Entomophthoromycota: Neozygitaceae). The results indicate no significant relation between the presence of conidia and predator behavior. The only indication of interference is between the generalists O. majusculus and M. brunneum, with a trend towards more time spent feeding and more prey encounters turning into feeding events on leaf discs without conidia than on leaf discs with conidia. Our results show that the presence of fungal conidia does not alter the preying behavior of the predators, and using predators and fungi together is not limited by any interference between organisms in the short term.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Tore SkrøppaAbstract
No abstract has been registered
Abstract
Accurately positioned single-tree data obtained from a cut-to-length harvester were used as training harvester plot data for k-nearest neighbor (k-nn) stem diameter distribution modelling applying airborne laser scanning (ALS) information as predictor variables. Part of the same harvester data were also used for stand-level validation where the validation units were stands including all the harvester plots on a systematic grid located within each individual stand. In the validation all harvester plots within a stand and also the neighboring stands located closer than 200 m were excluded from the training data when predicting for plots of a particular stand. We further compared different training harvester plot sizes, namely 200 m2, 400 m2, 900 m2 and 1600 m2. Due to this setup the number of considered stands and the areas within the stands varied between the different harvester plot sizes. Our data were from final fellings in Akershus County in Norway and consisted of altogether 47 stands dominated by Norway spruce. We also had ALS data from the area. We concentrated on estimating characteristics of Norway spruce but due to the k-nn approach, species-wise estimates and stand totals as a sum over species were considered as well. The results showed that in the most accurate cases stand-level merchantable total volume could be estimated with RMSE values smaller than 9% of the mean. This value can be considered as highly accurate. Also the fit of the stem diameter distribution assessed by a variant of Reynold’s error index showed values smaller than 0.2 which are superior to those found in the previous studies. The differences between harvester plot sizes were generally small, showing most accurate results for the training harvester plot sizes 200 m2 and 400 m2.
Authors
Alexander Kopatz Oddmund Kleven Jonas Kindberg Ilpo Kojola Jouni Aspi Göran Spong Niclas Gyllenstrand Love Dalén Ida Marie Luna Fløystad Snorre Hagen Øystein FlagstadAbstract
Background The populations of brown bear (Ursus arctos) in northern Europe have been recovering or are in the process of recovery from a severe demographic bottleneck. Especially in the main popula- tions of Scandinavia and Finland, the number of individuals has been increasing substantially, compared to the population sizes estimated 20 years ago. Also, the populations have spatially expanded, putatively restoring connectivity and gene flow between these two, formerly separated populations. The Swedish Environmental Protection Agency (Naturvårdsverket) assigned a pro- ject to assess the connectivity and gene flow between the eastern and western parts of Fen- noscandia, Finland and Scandinavia. Objective Our objective was to detect possible immigration of brown bears from eastern Fennoscandia, specifically Finland, into Scandinavia. Material and Methods For the first time with continuous sampling of brown bears, we assessed the population genetic structure and gene flow between the brown bear populations of Scandinavia and Finland. We based our analyses on the dispersing sex, male brown bears, as females tend to be philopatric. Our target area was the county of Norrbotten in northern Sweden, at the border to Finland and Norway, representing the most likely area for potential eastern immigrants into Sweden. Previous research did not reveal any influx from Finland into Sweden. However, brown bear samples from Norrbotten have to a very limited degree been included in earlier studies on genetic connectivity in the area. In addition to a large number of samples from Norrbotten and northern Finland, we included genotypes sampled in regions surrounding the target area: Västerbotten in Sweden, Troms and Finnmark in Norway and southern Finland. We utilized all samples and genotypes from male bears available, and, also, genotyped recently collected samples of male brown bears from the study area. Analyses on population genetic structure and gene flow among regions were based on 924 individual male brown bear STR-genotypes (12 short tandem repeats or microsatellite markers). In order to reveal patterns of male dispersal and the distribution of male linages we used brown bear samples genotyped with nine Y-chromosomal STRs from 826 males. KEY WORDS : connectivity, european brown bear, Fennoscandia, Finland, male gene flow, migration, population genetic structure, Scandinavia, Ursus arctos NØKKELORD : europeisk brunbjørn, Fennoskandia, Finland, genflyt, konnektivitet, migrasjon, populasjons genetisk struktur, Skandinavia, Ursus arctos
Abstract
No abstract has been registered
Authors
Jihong Liu ClarkeAbstract
No abstract has been registered
Authors
Franz-Sebastian Krah Ulf Büntgen Hanno Schaefer Jörg Müller Carrie Andrew Lynne Boddy Jeffrey Diez Simon Egli Robert Freckleton Alan C. Gange Rune Halvorsen Einar Heegaard Antje Heideroth Christoph Heibl Jacob Heilmann-Clausen Klaus Høiland Ritwika Kar Håvard Kauserud Paul M. Kirk Thomas W. Kuyper Irmgard Krisai-Greilhuber Jenni Nordén Phillip Papastefanou Beatrice Senn-Irlet Claus BässlerAbstract
Thermal melanism theory states that dark-colored ectotherm organisms are at an advantage at low temperature due to increased warming. This theory is generally supported for ectotherm animals, however, the function of colors in the fungal kingdom is largely unknown. Here, we test whether the color lightness of mushroom assemblages is related to climate using a dataset of 3.2 million observations of 3,054 species across Europe. Consistent with the thermal melanism theory, mushroom assemblages are significantly darker in areas with cold climates. We further show differences in color phenotype between fungal lifestyles and a lifestyle differentiated response to seasonality. These results indicate a more complex ecological role of mushroom colors and suggest functions beyond thermal adaption. Because fungi play a crucial role in terrestrial carbon and nutrient cycles, understanding the links between the thermal environment, functional coloration and species’ geographical distributions will be critical in predicting ecosystem responses to global warming.